QJsonDocument.toVariant() segfaults if JSON contains a null value

Minimal example to replicate crash:

from PySide2.QtCore import QJsonDocument

QJsonDocument.fromJson(b'{"test": null}').toVariant()

Which causes an immediate segfault.

For a hint at what may be going on, if you pass in a JSON document that contains an array with a null, rather than a null directly, like so:

from PySide2.QtCore import QJsonDocument

QJsonDocument.fromJson(b'{"test": [null]}').toVariant()

Raises a Python exception, not a segfault:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
RuntimeError: Can't find converter for 'std::nullptr_t'.

So perhaps what needs to be done is the Variant converters need to handle the special case of turning null values into Py_None